Software Bisque TPoint Telescope Pointing Software
TPoint for Windows Telescope Pointing Analysis Software can be used in conjunction with TheSky for Windows to analyze and improve the pointing accuracy of computer-driven telescopes. TPoint is currently being used on most of the world's largest telescopes to maintain pointing models and to monitor performance.
TPoint: An Advanced Telescope Pointing Analysis System
- Combined with The Sky Astronomy Software, TPoint provides you with all of the tools you need to efficiently analyze and improve the polar alignment and pointing performance of your computer-driven telescope. Using TheSky and TPoint in concert, you can rapidly select, target, and log telescope pointing data. TPoint can then graphically display the data in different formats to quickly reveal important characteristics of your telescope. After learning the inherent quirks and idiosyncrasies of your telescope, mount and optics, TPoint can automatically compensate for them, thus improving your telescope's pointing performance. TPoint even has an advanced analysis capability that enables you to determine axis misalignments, polar misalignment, gear errors, and more.
Key Elements for Precise Pointing
- High encoder resolution: TPoint is less effective with lower encoder resolutions.
- Repeatability: Try this simple "litmus" test with your mount. Slew to any star, then center the star in the eyepiece. Next, slew approximately 20 degrees away, then slew back. Is the star centered in the eyepiece? If not, your mount probably has "non repeatable errors" (backlash, out of round gears, mirror flop, etc.) that make it unsuitable for telescope modeling.
- Stability: Another simple test: center a star in the eyepiece, then gently push on (using a very small amount of force) one axis, then release. If the star does not return to it's original position, the mount may be unstable and result in poor overall pointing.
Sample TPoint Screen
- The screen shot below shows sample pointing data (the background "spreadsheet" data is acquired by pointing at known objects in using TheSky). It also shows TPoint's Fit dialog box. This dialog box allows you to specify which "terms" are applied to the pointing data to achieve optimal pointing and view the graphical RMS pointing results.
Sample TPoint Model
- The example TPoint model below was supplied by the Puckett Observatory
Graph of Telescope Pointing Before TPoint Model Applied
- The above screen shows the raw, unmodeled pointing data, indicating the telescope's all-sky pointing is about 3 arcminutes (199 arcseconds).
Graph of Telescope Pointing After TPoint Model Applied
- The above screen shows a graph of the telescope's RMS pointing after the TPoint model is applied. For this particular telescope, the pointing improved from 199 arcseconds RMS to just over 12 arcseconds RMS. Software Bisque's Paramount ME and GT-1100 customers routinely achieve RMS pointing of 30 arcseconds or less. What does this all mean? It means that if the telescope is slewed to an object, the object will most likely fall in the center of almost any optical system. No resynchronizing! No recentering! This translates to a more efficient, productive, reliable and easier to use observe.
Polar Alignment Help
- TPoint can also help you align your telescope to the celestial pole. After sufficient pointing data is acquired (30 or more points), TPoint will tell you how to adjust your mount to achieve the best polar alignment.
Support for Many Telescope Models
- TPoint can be used to improve the pointing accuracy of many commercial computer-driven telescopes, including:
- Paramount ME Robotic Telescope Mount
- Paramount GT-1100
- Paramount GT-1100S Robotic Telescope Mount
- Astro-Physics GTO GEM mounts
- Celestron NexStar GPS/CG/CGE telescopes and mounts (version 1.6 or later firmware is required for your Celestron hand paddle.)
- Meade LX200 and compatible telescopes
- Meade LX200 GPS (Autostar II) telescopes
- DFM Engineering telescopes
- Vixen Sky Sensor 2000
- Parallax GTO telescopes (using the AP GTO control system)
- Losmandy Gemini
- Takahashi Temma Mounts
- Telescope's supporting the Astronomical Command Language (ACL)
- Telescopes that use TheSky Telescope Control System (TCS)
TPoint in Action
- The same technology as found in TPoint for Windows is used at some of the world's great observatories. For example, TPoint maintains the pointing models and monitors the performance of the 8-meter Gemini telescopes, the Keck, UKIRT, and UKST telescopes (among others), and is currently being used to make the Anglo-Australian Telescope point to one arcsecond ƒ??????????? about the angular size of one of Jupiter's moons as viewed from earth.
Why not use TPoint for Windows to make your telescope pointing world-class!
Tips for Best Pointing
- The bottom line is TPoint works. That's why virtually every major observatory on the planet uses TPoint to improve telescope pointing.
How well? That depends upon the repeatability and stability of the telescope/mount/optical system.
- TPoint will significantly improve a telescope's all sky (RMS) pointing. Components that affect your telescope's ability to point (mechanical/optical axis alignment, mirror flop, gear out of round, tube flexure, etc.) vary from mount to mount; however, TPoint can usually achieve 45-60 second all-sky (RMS) pointing. With some minor mount modifications, even better pointing can usually be achieved.
- TPoint will quantify your polar alignment. Accurate polar alignment translates to improved telescope pointing, with or without TPoint.
- Random errors occur in all telescope/optical systems. The magnitude of the telescope's mirror flop, backlash, etc. all degrade telescope pointing performance. Minimizing these random errors can significantly improve any telescope's pointing performance (with or without TPoint).
- If your mount uses a Schmidt-Cassegrain (SCT) optical tube assembly, minimize SCT mirror flop and mirror shift for best overall pointing performance.
- Use a motorized focuser (Optec, RoboFocus, JMI SmartFocus, etc.) to minimize mirror shift. Although this will not improve pointing performance directly, it will make using your telescope much easier.
- Use a mirror stabilizer to minimize random mirror flop (for example, Software Bisque's C-14 Locking Collar or Scope Stuff's LX200 Mirror Stabilizer).
Minimum System Requirements
- Any computer running Windows 95ƒ??????????’??????????, Windows 98ƒ??????????’??????????, Windows Meƒ??????????’??????????, Windows NTƒ??????????’??????????, Windows 2000ƒ??????????’?????????? or Windows XPƒ??????????’??????????.
- At least 2 MB free disk space is required for installation.
- TheSky for Windows Level II, III or IV, version 5.00.044 or later must be installed on the computer.
- A TPoint compatible robotic telescope controlled via TheSky.